What goes around, comes around, goes the cliché. What’s going around a lot these days is walls, around neighborhoods and occupied territories and perhaps soon to be, around cities themselves—again. The U.S. in its endlessly silly, stupid and futile adventure in Iraq has walled itself off in an area called the Green Zone, a sealed redoubt from which Americans venture pretty much at their own peril these days, for much of the time it has been there. Ironically, the city that they captured with so much “shock and awe” has become their prison, outside of which friends and enemy cannot be discerned. Now the Bush administration is building (with our taxes) a wall around the Sunni area of the city that it is incapable (with our taxes), no matter how much they purge and surge, of protecting from the Shia insurgents. The Sunni don’t like the idea; they think they are being walled in. Maybe they are.
The Bush administration might be taking a cue from the Israelis who have become quite the wall builders of late, either walling out the Palestinians, or walling themselves in. What’s interesting about this wall building is that we might have thought that walls, which have a long history in urbanism had become an outmoded urban element. In most cities that had them they have been replaced by urban features that retain only some linguistic residue from their mural past. Many cities have boulevards, but only those that used to be walls—the word being derived from bulwarks—are worthy of the designation. Vienna’s walls became the renowned Ringstrasse that circles the central part of the city. In Paris, the last walls of the city are now the Boulevard Periphique that is the high-speed, grade-separated, limited access expressway.
What made walls obsolete the last time is still around—artillery. Walls were, for a long period of the history of cities, the primary form of urban protection. To be extra muros, or outside the walls, was a dangerous place to be for millennia. Walls kept out the bad guys, and great effort and expense were levied to keep one step ahead of their efforts sap, breach, and pound down city walls. Architects and scientists, some of great renown, like Leonardo Da Vinci and Scamozzi, put their minds to devising walls that would withstand the onslaughts of advances in ballistics and to ways in which they could be used offensively. Walls were, however, often breached, so attention was also given to urban design within the city. Hence, the meandering pattern of confusing narrow streets under one type of design would confuse and ensnare invaders, giving the townspeople the advantage of sniping at them and bottling them up. Other designs were more orthogonal, with the purpose of being able to deliver troops and ordinance quickly to any point on the walls where they were needed.
The best real estate for the period in which walls guaranteed some degrees of safety was in the middle of the town or city. This was furthest from the walls, and hence furthest from what could be launched, thrown or fired over them. Eventually walls became very elaborate, thick and crenellated, and assisted by trenches and moats to deny a direct angle to increasingly powerful cannon, and to optimize the advantage of return fire. Sometimes, as in the case of towns like Palmanova, the area of development devoted to the town’s defenses exceeded the settled area of the town.
But they could not last. Eventually, ballistics won the day. Better gunpowder and cannon permitted attackers to simply fire over the parapets from a safe distance and pound the city into submission. Long-range ballistics ushered in a whole new defensive approach to urban design; it became necessary to meet the enemy not at your walls, but in the field, well before they got close to your city. So broad avenues were installed that connected armories and barracks near the center of the city to the periphery. Troops and ordinance could be sent quickly in any direction from which threat came. Hinterland control was the new urban “wall,” and armies now clashed in the countryside and the winners got the undamaged city as a prize. This lasted right up to WWI, when armies used ride out to the battlefields, and then trenches, in taxicabs. The big cities were still relatively safe places to be.
But by WWII cities were back in the middle of international warfare. Most national wealth and industrial capacity were in cities, so to subdue an nation meant to subdue their cities. Since the mid-20 th Century defensive characteristics have been reversed. First the heavy bombers, then the ballistic missile, have made the least safest place to be in the middle of the large city and the safest place has moved to the perimeter and beyond. As we have learned, even commercial airliners have been “weaponized” to wreak havoc on the center of the city. The modern weapons of the Cold War not only made walls obsolete, some believed that they might make large cities themselves obsolete. 
But the most recent wrinkle, and one that the new walls are unlikely to have much of an effect upon, is the one that is driving the dimwits of the Bush administration bonkers— the urbanite as weapon. Bush, the neo-cons and uber-dolt Rumsfeld were well behind the curve, and are now well-ensconced behind the 8-ball. They thought that all they had to do is unleash all those technological goodies that most of our national wealth goes for, send in our soldiers looking like the Terminator and everybody would shout “Shoukran America!!! Welcome to our new democracy. Here, take our oil. Here, take my brother and torture him and debase him in front of your women soldiers. And yes, of course, we’ll be happy to convert to Christianity later. But first, have some more oil.”
Instead we got guys who would walk right up to your checkpoint, squeeze a button in their pocket and blow themselves and some of America’s fine young men and women to their respective afterlives. Instead, we got Humvees, and Bradleys, and even tanks blasted to junkyard scrap by cell-phones and explosives stupidly left behind by our troops who were off looking for will-o-the-wisp WMDs. Instead, we got insurgents and religious zealots and anybody else in the entire Middle East who wanted to get a shot off, or a bomb off on the American’s whose commander-in-chief, had called his war a “crusade.”
Instead we got the city is the battlefield, anywhere a sniper can get a shot off, an IED can be placed under a heap of garbage, or a suicide bomber can sidle up and blow an American soldier apart. This is urban warfare as down and dirty as it gets, and walling it off will be as futile as bailing a sinking boat with a sieve.
©2007, James A. Clapp (UrbisMedia Ltd. Pub. 4.26.2007)
 The DoD commissioned a large study with a major think tank after WWII. The concern was the appearance of buzz bombs and V2 rockets from Germany. The handwriting was on the wall, and the wall was in rubble. The result of the study was that, in future, the most effective way to defend against the ICBM was to de-concentrate our major metropolitan regions into towns of about 75 thousand, separated by 50 to 70 miles in distance. Anyone wanting the specific citations for these studies needs to write to me because I am unable to access the citation from Hong Kong.